Fuse plug



Sept. 23 1924, 1,509,272

L. VECCHIO FUSE PLUG Filed June 25. 1920 lllllllllllllla:

Mllllllll Patented Sept. 23, 1924.

UNITED STATES PATENT OFFICE.

LUIGI VECCHIO, OF SCHENECTADY, NEW YORK, ASSIGNOR T ELECTRICAL INVEN-TIONS & DEVELOPMENT COMPANY, OF SCHENECTADY, NEW YORK, A GOBPORA TION OFNEW YORK.

FUSE PLUG.

Application filed June 25, 1920. Serial No. 391,595.

7 '0 all whom it may concern Be it known that I, LUIGI Vnoomo, a subjectof the King of Italy, residing at Schenectady, in the county ofSchenectady and State of New York, have invented a new and useful FusePlug, of which "the following is a specification.

This invention is a thermal cut-out device for electric circuits.

One of the objects of the invention is to provide a fuse plug of simpleconstruction, which may be cheaply manufactured, and which may be madeto' perform all of the functions of standard devices of this type.

A further object is to provide a fuse plug having eflicient means formaintaining a fuse wire in operative position, in a manner which willpermit of its immediate renewal after it has been ruptured. A furtherobject is to provide a fuse plug, the parts of which may be readilyremoved for inspection and substitution of new parts, as occasion mayrequire.

The invention will be hereinafter fully set forth and particularlypointed out in the claims.

In the .accompanying drawing:-

Figure 1 is a side elevation illustrating a fuse plug constructed inaccordance with the invention. Figure 2 is a longitudinal sectional viewthereof. Figure 3 is atop plan view. Figure 4 is a bottom plan view.Figures 5 and 6 are detail views illustrating modifications of thecontact strip. Figures w 7 and 8 are longitudinal sectional viewsillustra-ting modifications of the fuse plug.

Referring to Figures 1 to 4 of the drawing, 10 designates the body ofthe plug, which is in the form of a casing constructed 4 of porcelain orother suitable insulating material, closed at one end and open at theother. Enclosing the lower portion of said body, is a screw shell 11,which is held from rotation relative to the body 10, in any desiredmanner. It is preferred, however, to.

provide the closed end of the body with a projection 12, which protrudesthrough a complemental openingin the shell, said projection and openingbeing shaped to prevent relative rotation. In the drawing the proiection12 is shown as of approximately eliptical form. The portion of the body10 through this C, thereby providing a very clear and deficontiguous tothe open end is provided with external screw threads 13, and the wall ofsaid body is provided with a longitudinally disposed channel 14, one endof which termmates at the open end of the body, the other end leading tothe outer surface of the body, at a point covered by the shell 11. Theclosed end of the body is provided with a longitudinally disposed bore15.

Mounted in the open end of thebod 10 is a contact strip 16, preferablyin the orm of an elongated rectangular plate, provided at one end with agroove in which is soldered, or otherwise secured, one .end of aconductor wire 17. Said strip is provided with an opening 18, ofpolygonal form, and also with a groove 19. The wire 17 extends throughthe channel 14 and contacts with but is not secured to the shell contact11, in a manner which will be clearly understood from the drawing. Thestrip 16 is supported in any suitable manner, preferably rest-' ing uponinternal shoulders located just inside of the open end of the body 10.

The rupturable fuse strip is preferably in the form of a wire 20, oneend of which is coiled around the shank of an anchoring device 21,slidably mounted in the opening 18 of the contact strip 16. The shank isof a cross-section complemental to the o ning 18, to prevent relativerotation. aid anchoring member 21 is provided with headed ends, one ofthe heads 22 being pressed inwardly by a cover plate 23, of insulatingmaterial to which clamping pressure is applied bymeans of an overhangingflange, formed on a screw shell 24, engaging the threads 13. In thismanner the wire 20 is clamped between said head 22 and the member 16, toinsure a perfect electrical contact. If desired the cover transparent.

To provide means for indicating when a I fuse is burned out, it ispreferred to form a hole in the cover plate 23 and to place therein apaper cap C. In the absence of other vents or holes, the heatedgasesmust escape hole by pushing out the cap nite indication of a blownfuse. Rigidly secured in the-bore 15, of the closed end of the plugbody, is a metal plate may be bushing provided with an outer flange 26.Slidably mounted'in said bushing is a tubular anchoring member 27,provided with inner and outer flanges 28 and 29, for

limiting its sliding movement, a transverse 'o enlng being formed insaid member contiguous to the flange 29. The lower end of the fuse wire20 is. passed through the bore of the anchoring member 27, and laterallythrough'the transverse opening therein, the extremity of said wire beingwrapped around the anchoring member in a position to come between theflange 26 of bushing 25 and the flange 29 of the anchoring member. i J

In practice, the inner end of the fuse wire 20 is secured to theanchoring member 27, in the manner above set forth, the other end beingengaged with the groove 19 of the anchoring device 21, and engaged withthe contact strip 16, in the manner heretofore described. The coverplate 23, and the clamping shell 24, are then secured in posisaid shellserving to force. the anchoring member 21 inwardly, causing the fusewire to be firmly gripped between it and the contactplate 16. Theclamping pressure exerted through the anchoring member also retains thecontact member in place. The plug is then ready for use and may beengaged withany standard socket, through the medium of the shell 11, theanchoring member 27 serving as the center contact. The circuit will thenbe completed through anchoring member 27, fuse wire 20, contact late 16,and conductor wire 17, to shell 11.

hould the wire 20 become ruptured from any cause, the plug is firstremoved from its socket, and clamping shell 24 unscrewed to permitremoval of the cover plate 23, which will expose the contact strip 16and its wire 17. The strip 16 is readily lifted out because the wire 20has been ruptured and the wirei17 is not attached to the shell 11.

After, removal of the strip 16, the shank of the anchoring member 21 maythen be pressed outwardly to free the contiguous end of the wire 20, andthe other end of the said wire may alsobe disengaged from the anchoringmember 27, by moving the latter outwardly to permit of saiddisengagement.

A new wire 20 may then be substituted, and

the parts all replaced, the whole operation requiring but very littletime, and the plug is again ready for use.

In lieu of providingthe contactstrip 16 with the polygonal opening andthe slidable anchoring member 21, said opening may be circular andprovided with internal threads to engage a binding screw 30,

around which the end of the wire 20 may be wrapped ina well-knownmanner. Such a construction is illustrated in Figure 5. 01' said platemay be provided with decircuit through the fuse wire.

tion, the clamping pressure produced by tion, and that the parts are sorelated that the pending legs 31 to retain it in position, asillustrated in Figure 6.

In Figure 7 is illustrated a modified arrangement of the means forestablishing the In this form, a body 10 is provided with a channel 14formed with a shoulder 32, which serves as a seat for a contact member33. One end of said contact member is shaped to engage the shell 11*,the other end being provided with an enlarged socket 34, shaped toengage said shoulder. The socket 34 receives the shank ofa headedanchoring member 35, around which the outer end of the fuse wire 20 iswrapped, said anchoring member being retained in position by a coverplate 23 and clamping shell 24'. The other end of wire 20, en gages alongitudinal groove in an anchoring member 27*, having headed ends, thecontiguous extremity of the' wire being wrapped around the shank of theanchoring member, between .the outer head and the end of the casing;

In Figure 8, is illustrated -another modification. In this form thecasing 10 is provided with a permanent center contact 36, and a shellcontact 11. The interior of said body'is provided with a contact plate37, having fingers 38 projecting through the wall of the casing intoengagement with the shell 11". The fuse wire 20 is mounted in asupporting frame or contact member 39, provided with an upper anchoringmember 21", and a lower anchoring member 27", the ends of said wirebeing engaged with said anchoring members. The anchoring members may beof any preferred form, but as illustrated they comprise headed shanksslidably mounted in the frame, and so arranged that the endsof the wiremay be clamped between heads thereof and the frame. Said frame isprovided with a contact member, 40 having resilient portions 41 engagingthe plate 37, the frame being held u ri ht b frictional enga ement ofthe P g 3 g tact 36, and the anchoring member 21 is held clamped againstthe frame 39, by the cover plate 23", which is retained in position bythe shell 24".

From the foregoing description it will be readily understood that theinvention provides a fuse plug of very simple construcwhich may becheaply manufactured,

fuse wire may be quickly renewed when necessary and that other repairsmay be made without difliculty.

Having thus explained the nature of the invention and described anoperative manner of constructing and using the same, although withoutattempting to set forth all of the forms in which it may be made, or allof the forms of its use, what is claimed 1. A fuse plug of the characterdescribed comprising a casing of insulating material having an internalchamber, a shell contact carried by said casing, a center contact, acontact member in circuit with the shell contact, a fuse wire removablyconnected at one end to said center contact and extended longitudinallythrough said chamber, means for anchoring the other end of said wire tosaid contact member, and means independent of the anchoring means forapplying clamping pressure thereto;

a 2. A fuse plug of the character described comprising a casing ofinsulating material, a shell contact carrier thereby, a center contact,a contact member in circuit with said shell contact, a freely movableanchoring member carried by said contact member, a fusewire having oneend connected to the center contact and the other end clamped betweensaid "anchoring member and said ,contact member, and means independentofthe anchoring member for applying clamping pressure thereto.

3. A fuse plug of the character described comprising a casing ofinsulating material, a shell contact carried thereby, a center contact,a contact member in circuit with said shell contact, an anchoring membercarried by said contact member, a fuse wire having one end connected tothe center contact and the other clamped between said anchoring memberand said contact member, and a cover plate positioned to engage saidanchoring member and through it to retain said contact member in place.

4. A fuse plug of the character described comprising a casing ofinsulating material, a shell contact carried thereby, a center contact,a contact member in circuit with said shell contact, an anchoring memberslidably mounted in said contact member and provided with a clampingportion, a fuse wireconnected at one end to said center contact andhaving its other end removably held between said contact member and theclamping portion of the anchoring member, and means for applying aclamping pressure to said anchoring member.

5. A fuse plug of the character described comprising a casing ofinsulating material, ashell contact carried thereby, a center contact, acontact member in circuit with said shell contact, an anchoring memberslidably contact member is retained in place through pressure applied tosaid anchoring member.

6. A fuse plug of the character described comprising a casing ofinsulating material, a shell contact carried thereby, a center contact,a contact member in circuit with said shell contact, an anchoring memberslidably mounted in said contact member and provided with a clampingportion, a fuse wire connected at one end to said center contact andhaving its other end removably held between said contact member andtheclamping portion of the anchoring member, and removablepressure-applying means p0- sitioned to engage the clamping portion ofsaid anchoring member, whereby said contact member is retained in placethrough pressure applied to the anchoring member.

7. A fuse plug of the character described comprisinga casing ofinsulating material, a shell contact carried thereby, a center contact,a contact member in circuit with said shell contact, an anchoring memberof conducting materialslidably supported by said contact member andprovidedwith a clamping portion, a fuse wire extending through thecasing and directly connected at one end to said center contact andhaving its other end removably held between said contact member and theclamping portion of the anchoring member, a cover plate positioned toengage the clamping portion of said anchoring member, and a screw shellremovably engaging said casing and having means for retaining said coverplate in place.

8. A fuse plug of the character described comprising a casing ofinsulating material, a shell contact carried thereby, a center contact,a contact member in circuit with said shell contact and provided with anopening of polygonal shape, a headed anchoring member having a .shankcomplemental to and slidably mounted in said opening, a fuse wireconnected at one end to said center contact and having its other endengaging said anchoring member, a cover plate- I I ing said cover platein position.

9. A fuse plug of the character described comprising a casing ofinsulating material provided with a chamber and having a channel in itswall leading from said chamber to an opening in the outer-surface of thecasing, a shell contact covering the said opening, a contact plate insaid chamber provided with an extension located in said channel andremovably contacting with said shell contact, a center contact, and afuse wire leading from said center contact to said contact member.

10. A fuse plug of the character described comprising a casing ofinsulating material ,provided with a chamber and having a channel in itswall leading from said chamber gaged by the respective anchoringmembers;

to an opening in the' outer surface of the casing, a shell contactcovering the said opening, a contact plate in said chamber providedwith'an extension located in said channel and removably contacting withsaid shell contact, an anchoring member mounted in said contact plate, acenter contact, a fuse .wire connecting said center contact and saidanchoring member, and means engaging said anchoring member to retainsaid contact plate in position.

llr-A. fuse plug of the character described comprising a casing ofinsulating material provided with a chamber and having a channel in itswall leading from said chamber to an opening in the outer surface of thecasing, a shell contact covering the said opening, a contact plate insaid chamber provided with an extension located in said channel andengaging said shell contact, an anchoring member slidably mounted insaid contact plate, a center contact, .a fuse wire connecting saidcenter contact and said anchoring member, a cover plate positioned toengage said anchoring member, and means'for applying a clamping pressureto said cover plate.

12. A fuse plug of the character'described comprising a casing ofinsulating material, a shell contact carried thereby, a contact membermounted in saidcasing and in circuit with said shell contact, a bushingmounted in one end of said casing, an anchoring member slidably mountedin said bushing and positioned to form a center contact, and a fuse wirehaving one end connected with said contact member and the other clampedin place by said anchor-' ing member.

13. A fuse plug of the character described comprising a casing ofinsulating material,

a shell contact carried thereby, a contact member mounted in said casingand in circuit with said shell contact, a bushing mounted in one end ofsaid casing, a'tubular anchoring member slidably mounted in said bushingand positioned to form a center contact, and a vfuse wire having one endconnected with said contact member andits other end passed through andclamped by said anchoring membe 14. A fuse plug of the characterdescribed comprising a casing of insulating material closed at one end,a shell contact mounted on said casing, an internal contact member. incircuit with said shell contact, an anchoring member slidably mounted insaid contact member, a second anchoring member slidably mounted in theclosed end of the casing and positioned to form a center contact, and afuse wire having its ends removably en- 15. A fuse plug of the characterdescribed comprising a casing of insulating material,

a shell contact carried thereby, a center contact, a contact memberremovable independently of the center contact, a fuse wire having oneend connected with the'center contact, an anchoring member looselysupported by the contact member and engaging the other. end of. saidwire, and means re movable with the contact member for placing it incircuit with the shell contact.

16. A fuse plug of the character described comp-rising 'a casing ofinsulating material, a shell contact carried thereby, a center contact,a contact member removable independcontact member, one end of saidcontact member having means removable with it for placing it in circuitwith the shellcontact, a

18. A fuse plug comprising a casing of insulating material, a shellcontact carried thereby, a center contact, an internal contact member incircuit with the shell contact, a slidable anchoring member looselysupported by said internal contact member, a fuse wire having oneend incircuit with the centercontact and the other end engaged with saidanchoring member, and

- means normally preventing slidable move-,

ment of the anchoring member.

19. A fuse plug comprising a casing of insulating material, a shellcontact carried thereby, .a center contact, an internal contact memberin circuit with the shell conr 20. A fuse plug ofthe character describedcomprising a casing 'of insulating material provided with a chamber andhaving -a channel inits wall leading from said chamberto an opening inthe outer surface of the casing,- a shell contact covering the saidopening, a center contact, a fuse wire havmg one end in circuit withsaid center contact, a loosely supported anchoring member to which theother end of said wire is connected, and a conductor member located insaid channel and incircuit with said anchor- 7 ing member and said shellcontact. 21. fuse plugcomprising a casing of lnsulatmg materiaha shell-contact carried anchoring member, and means normally preventingslidable movement of the anchoring member.

In testimony whereof I have hereunto set my hand.

LUIGI VECCHIO.

